Most milling cutters, e.g., side and end mills, have straight or spiral cutting teeth, but applicant is not aware of any form or milling cutter that has teeth with a constantly changing rake, i.e., from zero to positive rake, or from a positive to a negative rake. Applicant has devised such a tooth especially for side milling and as a particular instance, cutters for key cutting. These novel cutters are found to cut faster and cleaner than the usual cutters having straight line cutting teeth at the sides of the cutters.